What details in the description let you know that the figure is dead before it hits the ground?

From the text:

There was a speck above the island, a figure dropping swiftly beneath a parachute, a figure that hung with dangling limbs. The changing winds of various altitudes took the figure where they would. Then, three miles up, the wind steadied and bore it in a descending curve round the sky and swept it in a great slant across the reef and the lagoon toward the mountain. The figure fell and crumpled among the blue flowers of the mountain-side, but now there was a gentle breeze at this height too and the parachute flopped and banged and pulled. So the figure, with feet that dragged behind it, slid up the mountain. Yard by yard, puff by puff, the breeze hauled the figure through the blue flowers, over the boulders and red stones, till it lay huddled among the shattered rocks of the mountain-top.